Shimano Di2 Batteries. Must purchase battery, charger, and power cable to complete the system.
- Di2 External Battery, battery charger, and power cable are universal between Dura-Ace 7970, Dura-Ace 9070, Ultegra 6770 and Alfine Di2 systems
- Battery weighs 71g
- All Di2 components on the bicycle require the same firmware version. Using Di2 components with different firmware versions may cause malfunctions
- Use Di2 system checker to update component firmware from http://e-tubeproject.shimano.com/